To analyze the inelastic neutrons scattering intensities, we calculated the neutron scattering cross section of the magnon excitations using the SpinW program [1]}. The magnon calculation was based on the linear spin wave approximation within the Holstein-Primakoff formalism. The least square fitting was performed between the observed and calculated intensities over the same wave vector ranges, from which we obtained the best-fit exchange constants. The model spin Hamiltonian and the parameters included will be discussed in the next section.
